International tensions over the war in Ukraine have escalated with the US warning about a potential Russian air strike on its embassy in Kyiv.

The warning follows the first use of US-supplied missiles to strike targets deep inside Russia after US President Joe Biden granted permission to Volodymyr Zelensky’s forces.

The UK Government, which is considering its own position on whether to give Kyiv permission to use British-supplied weapons against targets inside Vladimir Putin’s country, said it was looking closely at the security situation for its own embassy.

The US state department said it had received “specific information of a potential significant air attack on November 20” and “out of an abundance of caution, the embassy will be closed, and embassy employees are being instructed to shelter in place”.

The UK’s Science Secretary Peter Kyle said the Government was looking closely at the situation and “we will do everything we can to keep British citizens safe”.

The British embassy in Kyiv has been operating a limited diplomatic function in recent months.

Mr Kyle told Times Radio: “I’m not going to share details at the moment of operational matters that are on the ground in Kyiv.”

The minister offered assurances that the situation is being looked at “incredibly closely” by the Government.

He added: “We have very good relationships with the government in Kyiv and with the United States. We will do everything we can to keep British citizens safe.

“But there’s just been no doubt this conflict has gone on for over 1,000 days now. It was caused by the illegal, unwarranted and unprovoked attack by Vladimir Putin.”

He said the conflict “could be brought to an end instantly, if Vladimir Putin himself decided to de-escalate, rather than continually escalate the circumstances around this conflict”.